Internal-combustion engine starter



Get. 5, 1954 c. E. LINCOLN INTERNAL-COMBUSTION ENGINE STARTER 3 Sheets-Sheet 1 Filed Sept. 14, l95l C(ttornegs Oct. 5, 1954 c. E. LINCOLN 2,691,110

INTERNAL COMBUSTION ENGI NE STARTER Filed Sept. 14, 1951 3 Sheets-Sheet I5 3nventor Gttornegs Patented Oct. 5, 1954 UNITED STATES ATENT OFFICE This invention relates to powered outdoor equipment driven by internal combustion engines, as for example automobiles and the like, and more particularly to a mechanism for automatically controlling the engine. In several embodiments of the invention the mechanism periodically operates the engine when the equipment is idle in cold weather, to maintain engine temperatures above a predetermined value. In another em bodiment of the invention the mechanism shuts off the engine after it has idled a predetermined time. The present invention is a continuation in part of my copending application, Serial No. 193,985, filed November 3, 1950, entitled Automatic Control for Internal Combustion Engine.

In this copending application there is described and claimed an automatic control employing a thermal cutout to render the control inoperative in the event that the internal combustion engine should fail to start after a number of attempts, for example three or four. This cutout is of the manually resettable type, and after functioning maintains the control inoperative until such time as the cutout is reset.

While the cutout of my application above referred to operated satisfactorily where temperatures were not extremely low, it sometimes did not function in sub-zero weather where temperatures dropped considerably below freezing. In other words, the eifect of sub-zero ambient temperature at times prevented the cutout from operating to render the control inoperative, and

in such event the control did continue to function and ultimately drained the battery or other source of power.

Also, in the control of my copending application the thermal cutout was warmed or actuated by a resistor placed in series with the feed circuit for the ignition coil, starter relay and other apparatus such as the heater motor, etc. Such series connection resulted in a voltage drop which therefore decreased the voltage available for the coil, relay, heater motor, etc., and while this voltage drop was of small magnitude it is nevertheless considered undesirable because of the reduced eiiiciency of storage batteries when subjected to low temperatures.

The above disadvantages of my prior control are overcome by the present invention, which has for its object the provision of an improved control of the type described which is reliably operative over a wide range of ambient temperatures including sub-zero, and the provision of a control which will not reduce the voltage available for the ignition coil, etc.

Another object of the invention is to provide an improved control as above set forth, which is simple and economical to produce, and which is reliable in its operation.

In accomplishing the above objects I provide a control with thermal cutout wherein the heat ing current for the cutout is obtained through a shunt path, being different from the series current which passes through the cutout and which supplies the ignition coil and other equipment. Thus there is eliminated the objectionable voltage drop which characterized my prior construction and which served to decrease the voltage available for the electrical components required in starting the engine. The heating current in the shunt path required to energize the heater for the thermal cutout is relatively small and therefore does not appreciably affect the voltage of the supply or battery.

In the specific embodiments of the invention illustrated herein the shunt path in which the heater is connected includes a pair of auxiliary contacts on a relay forming part of the control, and by this organization energization of the heater for the thermal cutout can be effected only during the intervals when the engine is being cranked by the starter.

In one illustrated form of the invention the heater for the thermal cutout is provided with a tap connected in circuit with a bimetallic switch whereby a portion of the heater will be cut out automatically when the ambient temperature reaches a predetermined low Value. With this construction the heater will draw higher current and provide more heat when the ambient temperature drops.

In another illustrated form of the invention a casing is provided around the thermal cutout, having a heating coil controlled by a bimetallic switch whereby the casing is electrically heated when the ambient temperature drops below a predetermined low value.

In accordance with this invention auxiliary equipment such as a car heater may be operated by the engine control, thereby to heat the in terior of the car at the same time that the engine is being warmed up. The additional electrical load imposed by the heater motor will not appreciably detract from the voltage available for the ignition coil because of the elimination of the drop resistance in the thermal cutout.

A further object of the invention is to provide, in conjunction with the cold weather engine control, an improved and simplified automatic 3 engine shutoff means for an automobile which is used for delivery or pick-up service, such shutoff functioning in the event that the time of a call exceeds a predetermined duration, to

shut off the idling engine and thereby save gasoline.

Still another object of the invention is to provide an improved delayed-action cutout to render the system inoperative in the event of repeated unsuccessful attempts to start, said cutout being reliable and at the same time simple and economical to fabricate.

Yet another object of the invention is to provide a greatly simplified engine control coordinated with the generator of the engine to effect deenergization of the starter motor.

Other features and advantages will hereinafter appear:

In the accompanying drawings:

Figure 1 is a schematic diagram of one form of improved engine control of the present inventicn, applied to an automobile.

Fig. 2 is a schematic diagram of a modified form of thermal cutout, for use with the circuit diagram of Fig. 1.

Fig. 3 is a schematic diagram of still another form of thermal cutout for use with the circuit of Fig. 1.

Fig. 4 is a side elevational view of the thermal cutout unit shown in Fig. 3.

Fig. 5 is a schematic diagram of an engine control illustrating another form of the invention, characterized by a single-pole shift-controlled switch and a double-pole manual on-andoff switch, together with automatic engine shutoff means for use where the vehicle is employed for delivery service.

Fig. 6 is a schematic diagram of a starter circuit and part of a control circuit, illustrating an insulated type of starter relay to replace part of the circuit of Fig. 5.

Fig. '7 is a schematic diagram illustrating a generator-controlled cutout switch to replace the vacuum control of Fig. 5.

Fig. 8 is a schematic diagram illustrating an oil pressure type of cutout, to replace the vacuum control of Fig. 5.

Fig. 9 is a schematic diagram of another form of improved engine control having a generator cutout and a simplified relay means.

Fig. 10 is a schematic diagram of a starter circuit and control circuit to replace part of the circuit of Fig. 5.

Referring to Fig. 1 there is shown an automobile engine control comprising a source of electricity such as a battery Ill, having one side or terminal connected to a ground H. The other side of the battery is connected with the starter circuit for the engine, comprising a wire l2 connected to a relay starting switch l3 which is in turn connected by a wire 4 with a starting motor having a ground connection H5.

The relay switch i3 is actuated by the coil ii having one end connected to the wire l2 and the other end connected to a wire IS in turn connected to switch contacts is of a relay 20. The switch I9 is grounded at 2|, and is actuated by a coil 2011. connected to a ground 22.

Energization of the coil 26a closes the switch l3, effecting energization of the coil l! which breaker points 28 which are connected to a 4 ground 21 and a wire 28 joined to the primary 29 of an ignition coil 30. The coil 39 has a seccndary 3| connected to a ground 32 and by means of a wire 33 to the rotor 24 of the distributor. The distributor has high tension leads 34, 35, 38 and 37 which are to be connected with spark plugs (not shown) all in the well known manner.

As in my copending application above referred to, the ignition coil primary 29 is connected through a wire, indicated as 38, to a heat responsive switch 39 arranged to close when the engine temperature drops below a predetermined value. The switch 39 may have a bimetallic actuator 46 and a heating element 4|, the latter being connected to the wire 38 and to a contact 42 cooperable with a movable contact 43 which is actuated by a bellows 44 operated by vacuum introduced through a pipe line 45.

The pipe line 45 is to be connected to the intake manifold (not shown) of the automobile engine whereby operation of the engine will separate th contacts 42 and 43 as a consequence of the vacuum existing in the intake manifold.

The contact 43 is connected through a wire 45 to a double-pole single-throw switch 47 which is actuated by the shifting mechanism 48 of the automobile. Details of the shift-actuated switch may be found in my copending application above referred to. The organization is such that the switch 47 is closed only when the shifting mechanism is in neutral position, and is open at all times that the shifting mechanism is in any gear, either forward or reverse. The switch 47 is connected by a wire 49 with the relay coil 20c, and by a wire 50 with an ambient-temperature controlled switch 5|, preferably bimetallic, said switch being connected by a wire 52 to the battery [0.

An ignition switch 53 is shown, connected by wires 54 and 55 respectively to the wires 38 and 52.

A manually operable starter switch 56 is connected by a wire 51 to the wire I8 and also connected to a ground 58, the switch 56 thus controlling the energization of the starter relay [3. Also, a heater motor 53 is connected with the wire 38 and with a ground 59a as shown, to be automatically controlled by the ignition switch 53.

In accordance with the present invention a novel and improved thermal cutout 60 is provided whereby the control system will be rendered inoperative whenever the engine fails to start after several unsuccessful attempts, as for instance three or four, said cutout being characterized by a heating means which is independent of current supplied to the equipment of the automobile such as the ignition coil 30, heater motor 59, relays l3 and 21, etc. By this organization there is obviated any undesired and disadvantageous voltage drop in the cutout 80, such as characterized the thermal cutout of my 00- pending application above referred to. The present improved thermal cutout, instead of using a heater in series with the circuit supplying the electrical equipment of the car, utilizes a heater having a shunt connection with respect to said equipment. Accordingly, this equipment will have available the full voltage of the battery ID, without having detracted from it any voltage drop through a heater.

The present improved cutout comprises a bimetallic manually resettable switch 6| connected by a wire 62 to the shift controlled switch 41. The cutout 6|] also includes a manually operable on-off switch 63 connected by wires 64 and 65 respectively to the switches 6i and. 39. A pilot light 56 is provided, connected to the wire 65 and to a ground 6i.

Automatic actuation of the bimetallic switch ii is accomplished by means of a heating coil 68 connected to the wire 64, and connected through a wire 69 to auxiliary contacts ill on the relay 26 which are also connected to a ground ll.

Operation of the improved control shown in Fig. 1 is as follows: When the driver leaves the vehicle after operating it, the engine will be warm and the bimetallic switch 39 will be open as shown. If the driver desires the control to be operative, he closes the manual switch 63, and places the car in neutral, this latter closing the double-pole single-throw switch 41. These switch positions are indicated in Fig. 1.

The ambient temperature controlled switch 5| is normally closed in cold weather, being open only when the weather is so warm that a driver would not desire the control to be operative.

After the engine has been shut off and its temperature drops, a point will be reached where the bimetallic switch 39 closes. Upon this occurring, the ignition coil 30 will be energized, as will the heater motor 59 and the relay coil 28a. The latter will close the relay switches l3 and is, resulting in energization of the starter relay ll, and energization of the starting motor l5. The engine will thus be cranked.

Upon the engine starting, the bellows 44 will be immediately actuated to separate the contacts i? and 43, thereby de-energizing the relay coils 28a and I1 and de-energizing the starter motor Iii. The engine will now continue to operate until its temperature rises to the point where the bimetallic switch 39 functions to open the circuit. This will disconnect the ignition coil 3t and result in the engine ceasing to operate.

If, after an initial cranking of the engine it should fail to start, the current passing through the heater 4! will create sufficient heat to open the bimetallic switch 39 without benefit of heat from the engine. Such action will disconnect the ignition coil 30, heater motor 59 and starting motor l5, together with the relay coils a and I1.

Upon this occurring a second attempt to start the engine will be automatically made as soon as the bimetallic switch 39 cools sufficiently in consequence of the heater 4! being de-energized.

The above cranking cycle will now be repeated when the switch 39 closes, and such repetition may occur several times until the engine starts.

If, after several attempts to start the engine it still does not start, the heat produced by the heater 6-8 will accumulate in the thermal cutout 50 and will actuate the switch 63 to permanently open the circuit. The switch 6| is of the type which requires being manually reset after it has once been actuated to open position. Thus there will be prevented further operation of the control, to unnecessarily drain the battery It.

It will be observed that none of the current required by the ignition coil 30, heater motor 59, heater M, or relay coil 20a passes through the heater 68. In other words, the heater 58 is not in series with the circuit supplying such equipment with current. Accordingly there is no voltage drop in said circuit due to the heater 6'8, and such equipment will be provided with the full voltage supplied by the battery It. The heater 68 is instead connected in a shuntcircuit comprising th wire G9, relay switch 78 and ground H, said circuit being in shunt with the ignition coil 3!], heater motor 59, etc. The said shunt circuit does not therefore reduce the voltage available for the ignition coil and other equipment, and this is an important advantage when it is considered that the efficiency of the battery it is materially decreased when it is subjected to very low temperatures, as for example sub-zero temperatures.

In Fig. 2 there is shown a novel, improved thermal cutout unit provided by the present invention, which is so arranged and constituted that it will operate with reliability even though subjected to sub-zero ambient temperatures.

The thermal cutout unit "62 shown in Fig. 2 has connecting wires "l3, l4 and 75, and a ground connection it which may be respectively substituted for the wires 62, 69, 65 and the ground Bl, with the cutout l2 substituted for the cutout 65 shown in Fig. 1.

The cutout unit 72 includes the manually operable switch E53 and the bimetallic switch 6|. It also includes the pilot light 56. For the purpose cf actuating the bimetallic switch 6! a heater ii is provided, connected with the switch 53 and with the wire 14. The heater "H has a tap it intermediate its ends, adapted to be engaged by a bimetallic switch arm is connected with one end of the heater i? as shown. The bimetallic arm i9 is arranged to be normally open when ambient temperatures are not extremely low. However, when the ambient temperature falls to sub-zero values, the arm :9 will be actuated to engage the tap 58, thereby short circuiting part of the heater ll. Accordingly the heater will draw more current from the battery it? and. will produce a greater amount of heat to actuate the bimetallic switch 6|. Thus the effect of the sub-zero ambient temperature is counteracted or compensated for, and such low temperatures will not result in the thermal cutout 72 being rendered inoperative. This is an important advantage in the device of the present invention in that it insures the control being rendered inoperative after several unsuccessful attempts to start the engine have been made, and thereby protects the battery It from being unnecessarily drained of energy.

Another cutout unit of the invention is illustrated in Figs. 3 and 4. The thermal cutout at in these figures has lead wires 3!, 82 and 83 adapted to replace respectively the wires 62, Ed and as to enable the cutout 8!] to be substituted for the cutout 6B.

The thermal cutout unit at includes the manually operable switch 63, thermostatic switch ti and heater 68. Also, it includes the pilot light 655 and ground connection 67.

Referring to Fig. l, the thermal cutout 8i; is provided with a casing 8d having a face plate 8-5 through which a reset button tit for the switch iii extends.

By the present invention the casin 25 i is provided with a heating coil 8? having its ends connected with terminals 83 and 8t. Within the casing 8 a second bimetallic switch Qt is located, connected in series with the heating element 8! and also connected with a ground 9 i.

The bimetallic switch is so adjusted that it will remain open during cold weather which does not have abnormally low temperatures. It, however, the temperature becomes abnormally low, as for example sub-zero, the switch 93 will automatically close, connecting the heating coil 8? for energization. This willheat the casing 34 and warm the air inside the casing, which surrounds the bimetallic switch 6 I. Accordingly, the switch SI will operate in a normal manner in response to heat from the heater E8, and will not fail to function to render inoperative the control in the event that the engine fails to start after several tries.

An automobile engine control having a singlepole shift-controlled switch, and having a doublepole manual on-and-off switch, is shown in Fig. 5. The circuit of Fig. includes a battery 92 connected with a ground 93, and by means of a wire 94 with a non-insulated type relay starting switch 95. The switch 95 is connected through a wire 98 with a starting motor 9! which is in turn grounded at B8. The relay starting switch 95 is controlled by a coil 239 having a ground I36 and having a lead It! through which it is energized.

The battery 92 is connected by a wire It! to a single-pole shift-controlled switch I03 actuated by the shift mechanism IE4 or the vehicle. As in the circuit of Fig. 1, the switch I63 is open for all running positions of the shift mechanism I64, the exception being th neutral position for which the switch I83 is closed. A wire I95 connects the switch I63 with a thermal cutout unit I86 having a bimetallic, manually resettable switch It! controlling the circuit of the wire I95. From the switch IS? a wire I68 connects to one pole of a double-pole manual on-andoff switch I08 connected by a wire I I8 with a heat-responsive switch II I. From the switch II I a wire IE2 leads to the other pole of the manually operable switch I69, said other pole being connected through a wire I I3 to the primary II-i of an ignition coil H5. The primary of the coil I15 also connects through the wire I IS with distributor points II'I connected by wire H3 with a ground H8. The distributor points II? are actuated by a cam I28 coupled to a distributor rotor I2I arranged to feed spark plug wires I22, I23, I24 and I25. The rotor I2i is energized from the secondary I26 of the spark coil II5, said secondary being grounded at I21.

In the thermal cutout unit I96 a pilot light I28 is provided, connected by a wire I29 with the wire I Ill, the pilot light being grounded at I30.

The heat-responsive switch I II has a bimetallic actuator I3I responding to a heating coil I32 connected by a wire I33 with the wire H2. The coil I32 is also connected with a cutout switch I 34 in turn connected by a wire I35 with a magnet coil I36 of a double-pole relay I37. said coil being grounded at I38.

Automatic control of the switch I34 is effected by a bellows I34a connected with a vacuum line I341) of the car. The establishing of a vacuum in the line It ib will compress the bellows and open the switch I34. One pole of the relay IS'I is connected with the wire IIEI and also with a wire I39 which in turn connects with the wire H0. The other pole of the relay I3? is connected by a wire I50 with a heater coil I lI in the thermal cutout unit I83, said coil having its other end connected by a wire I42 to the wire I M3. The said other pole of the relay switch I3'I is also connected by a wire I 3 to a heater coil I 44 grounded at Hi5, and the coil I44 is bridged by a short-circuiting bimetallic switch I46 responding to heat from the coil by closing. If desired, a current-limiting resistor I46a may be connected in series with the switch I46.

In accordance with this invention, in conjunction with the above circuit novel and simplefied means are provided, to be made operative by the 8 driver, for automatically shutting off the engine if it should be left idling for more than a predetermined length of time. This means is of advantage in certain circumstances, such as where the car is used for delivery service and the like, since an unexpectedly long call could result in the engine running uselessly for an extended period of time, wasting gasoline.

As shown, this shutoff comprises a single-pole double-throw switch I4? having its blade I58 connected by a wire I49 with the wire I I3. The two contacts I50 and I5I of the switch I4! are bridged by a bimetallic heat-responsive switch I52 one terminal of which is connected by a wire I53 with the ignition switch I54, the latter bein in turn connected by a wire I55 with the battery lead I02. The wire I53 is connected to a heater I56 which is grounded at I57. Ihe blade I48 of the switch I47 may be manually actuated in any suitable manner, as by means of a cam or eccentric I58.

Operation of the improved control device shown in Fig. 5 is as follows: If in cold weather the operator intends to leave the car for any length of time and desires to have the engine temperature maintained above a point where starting is difficult, he closes the double-pole manually operable switch I69 and places the gear shift lever Ice in neutral position before leaving. Shifting the lever m4 to neutral closes the switch I93. The heat-responsive cutout I96 is normally closed. When the temperature of the engine falls below a predetermined value, the heat-responsive switch III will close, energizing the ignition coil IIIS through the wires IE2, I85, I98, III], H2 and H3. At the same time the heater I32 and relay I3! will be energized through the circuit including the wires I33 and I35. The contacts of the relay I37 will thus be closed, energizing the starter relay switch through the wires I39 and IGI and energizing the heaters MI and I43 through the wires I42, I43 and I43.

Energization of the starter switch 95 will cause the engine to be turned over with the ignition on, and normally this will start the engine. Upon the engine starting, the bellows I34a will be immediately actuated by the vacuum in the line I341), opening the switch I34 so as to de-energize the relay I3? and open the starting switch 35. The engine will now run at idling speed, or slightly faster depending on the throttle setting. After the engine has run for a predetermined length of time to raise its temperature, the bimetallic arm I3I will be actuated to open the switch III, disconnecting the ignition coil I I5 and stopping the engine. The cycle will then be repeated when the engine temperature again falls sufliciently to close the switch III.

II", when the engine is initially turned over several times it will not immediately start, the circuit through the starter switch 95 will be opened as follows: Of the three heat-responsive switches I96, I45 and III, the latter is made the quickest to react to its associated heater. Thus, if the engine does not start after a predetermined cranking, the circuit controlled by the switch I II will be opened, disconnecting the ignition coil, the relay I3! and the starter switch 95. Another attempt to start the engine will be made when the bimetallic arm I3I cools as a consequence of disconnection of the heater I32. After several unsuccessful attempts to start the engine have been made, the heater I44 will have produced sufficient heat to close the bimetallic switch I45, and this will in turn cause a greater energization of 9 the heater I4! when the next try to start the engine is made. Such greater energization of the heater MI will actuate the cutout N38 to permanently open the circuit until it is subsequently manually reset by the operator. Thus unnecessary drainage of energy from the battery 55 is prevented. Overload protection for the resistor MI and cutout m8 is provided by the resistor I 55a.

If the vehicle is to be used for delivery service where the driver lets the engine idle while making a call, the automatic engine cutoff feature of the invention may be brought into use. To do this, the driver actuates the eccentric I53 to bring the switch blade I IB into engagement with the contact I5I. Normally the heat-responsive switch I52 is closed so that such actuation of the eccentric will connect the wire I 53 through the switches I52 and I4! with the wire I I3. When the vehicle if left with its engine idling the ignition switch I54 will normally be closed. This will cause current to flow through the heater I55 and after a predetermined interval of idling the heat generated will actuate the bimetallic switch I52 to open the circuit through the ignition coil I I5 and thereby stop the engine. Upon the driver returning to the vehicle he can throw the switch I I"! to the left and again start the engine.

It will be noted that in the circuit of Fig. 5 I have eliminated the double-pole shift-controlled switch shown in Fig. 1, and utilize instead a simple single-pole switch controlled by the shift lever more readily available on the market. Also the circuit of Fig. 5 utilizes an easily obtainable double-pole manually operable on-ofi switch in place of the single-pole on off switch shown in Fig. 1, and incorporates the novel time delay for the thermal cutout I65, in the form of the heat-responsive switch I 45 and heater I44 therefor In Fig. 6 there is shown a circuit diagram incorporating an insulated type of starter switch, which may be replaced for the non-insulated starter switch 95 shown in Fig. 5. The circuit of Fig. 6 may be substituted for that portion of the circuit of Fig. 5 included in the rectangular broken outline X, and for convenience in making the substitution the wires I39, I35, MI) and M have been provided respectively with terminals A, B, C and D indicating where the separation and substitution of the circuit may be made.

Components illustrated in Fig. 6 which are similar to those of Fig. 5 have been given identical characters. The difierences which characterize Fig. 6 are as follows: The wire I 39 which in Fig. 5 has the terminal A is not brought out to such terminal in Fig. 6, but instead is grounded at I591. The end of the starter switch coil 99 which in Fig. 5 is grounded is not grounded in Fig. 6, but instead is connected by a wire I65 with the wire 94. Operation of the control with the circuit of Fig. 6 substituted for the corresponding portion in Fig. 5 is identical to that already described with the exception that the starter switch coil 95 has its polarity changed by virtue of the shifting of the ground, whereby the coil is grounded through a contact of the relay I31 instead of being permanently grounded (as shown in Fig 5) and energized through the contact of the relay I31.

In Fig. 7 a schematic diagram is shown, illus trating a generator controlled circuit breaker to be substituted for the pneumatic or vacuum-operated circuit breaker of Fig. 5. The circuit of Fig. 7 may be substituted for that portion of the circuit of Fig. 5 enclosed in the broken outline "10 labelled Y, and for convenience in making the substitution the wires I39, I35, III! and H2 have been provided respectively with terminals E, F, G and H. In Fig. 7 components which are identical to those found in Fig. 5 have been given like characters.

The cutout switch I35 in Fig. 7 is actuated by a magnet coil I5I grounded at I52 and connected by a wire I53 with the car generator Iii I which is grounded at I65. Operation of the control apparatus with the circuit of Fig. 7 substituted for the corresponding portion of the circuit of Fig. 5 is similar in most respects, with the exception that when the engine starts up the current provided by the generator its will energize the coil I6I to open the switch I34, as distinguished from said switch being opened by the bellows IBM of Fig. 5.

In. Fig. 8 there is shown a schematic diagram illustrating a cutout switch actuated in response to liquid pressure, such oil pressure of a vehicle engine. The circuit of Fig. 8 may be substituted for the portion of the circuit of Fig. 5 enclosed in the broken outline Y, having the terminals E, F, G and H. Components of the circuit of Fig. 8 which are identical with those of Fig. 5 have been given like characters.

In Fig. 8 a pressure-responsive switch :55 is provided, having a movable diaphragm I5? controlling switch contacts I58 one of which is connected with the heater I32 and the other with the wire I35. The switch I66 has a casing I69 connected to an oil pressure line llll of the vehicle engine. When the engine starts up, the oil pressure in the line I!!! will separate the contacts of the switch I58, de-energizing the wire I35. This operation replaces the vacuum actuation of the switch I3 l described previously in connection with Fig. 5.

Another embodiment of the invention is illustrated in Fig. 9. Components of the apparatus shown in this figure which are identical to those of Figs. 5 and 7 have been given like characters.

Considering the difierence of the circuits, in Fig. 9 the magnet coil I6! controls not only the cutout switch I35 but also a second cutout switch I'II having one terminal connected by a wire I12 with the wire I33 and having its other terminal connected by a wire I73 with the starter switch coil 99. The cutout switch I3 1 is connected by a wire I'I I with a heater I75 grounded at I it, said heater controlling a bimetallic switch I I! connected by a wire lit with the thermal cutout heater MI. The switch I'I'I is connected to a. resistor I79 which is grounded at I88.

In the operation of the control illustrated in Fig. 9, starting of the automobile engine will open the switches I 35 and I'll, tie-energizing respectively the heater I75 and the coil 98 of the starter switch 95. If the automobile engine should not start after several repeated trials, the heat accumulated at the heater II5 will actuate the bimetallic switch IT! and close the latter, connecting the heater MI in the circuit so that at the next unsuccessful attempt to start the engine, the thermal cutout IIIE will be actuated to permanently open the circuit until it is again manually reset.

Fig. 10 shows a circuit diagram which may be substituted for the blocked portion X of Fig. 5 to effect several advantages. For example, in Fig. 5 four terminals A, B, C and D are utilized whereas with the circuit of Fig. 10 substituted, only the terminals A, B and D would be utilized, eliminating one lead wire. In addition to eliminating the lead connected with the terminal C,

there would also be eliminated the resistors III and Wm, thereby reducing the number of components required.

Another advantage provided by the circuit of Fig. 1.0 is that, where the starter relay 99 draws a very heavy current this will not affect the reset breaker I06, since the current for the starter relay will now be provided through the lead 94 from the battery 92 and not through the switch I00.

Parts in Fig. 10 which are similar to those of Fig. 5 have been given like characters. New parts or connections are as follows: A wire I8I connects the lower pair of contacts of the relay I31 with the wire 94. The current limiting resistor I46a is omitted from the circuit of the bimetallic switch I46. The upper pair of the relay contacts I3! is connected by a wire I82 to the terminal A, and said terminal is not now connected through wire I39 to the lower pair of contacts. Other connections are as previously described.

Operation of the apparatus incorporating the circuit of Fig. 10 is in general similar to that already described above, with the exception that the starter relay coil 99 receives its energization from the wire IBI connected to the cable 94, in-

stead of being energized through the switches I09 and I09. Accordingly the switch I08 is independent of the current drawn by the relay coil 99, which varies with different cars and may in some instances be quite substantial.

It will be noted that, with the circuit of Fig. 10 substituted for the corresponding circuit in Fig. 5, the heating efiect of current passing through the switch I06 is depended on to open the switch,

rather than any transfer of heat from the heater I4I which is now omitted.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. A control for an internal combustion engine having an electrical ignition circuit, comprising a single-pole double-throw manually operable switch having its blade and one contact connected in said ignition circuit; a heat-responsive switch connected across the contacts of the firstnamed switch; and a heater for said heat-responsive switch, having one end connected to the heat-responsive switch and having its other end grounded.

2. A control for an internal combustion engine having a starter circuit and a source of electricity, comprising means for connecting .said circuit to said source when the engine is not running, in response to the engine temperature dropping below a predetermined value; and means for disconnecting said circuit and said source whenever said first connection persists beyond a predetermined time, including a thermostatic switch in said circuit and a heater for said switch, and including a second thermostatic switch series connected to said heater and a second heater bridged across the second thermostatic switch.

3. A control for an internal combustion engine having a starter circuit and a source of electricity, comprising means including a control circuit for connecting said starter circuit to said source when the engine is not running, in response to the engine temperature dropping below a predetermined value; and means for disconnecting said starter circuit and said source whenever said first connection persists beyond a predetermined time, including a thermostatic switch in said starter circuit and a heater for said switch, and including a second thermostatic switch series connected to said heater and a second heater for said switch, connected to said control circuit.

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